Apple has long been obsessed with secrecy, but a new memo seems to take it to the next level. Bloomberg’s Mark Gurman reports on a memo recently sent to all Apple employees stating that 29 Apple people were caught leaking secrets about planned products last year, and 12 of them were arrested. The memo describes in stark terms the implications for employees who leak and get caught: “These people not only lose their jobs, they can face extreme difficulty finding employment elsewhere,” says product marketing executive Greg Joswiak in the memo.

The memo lays out examples of times when whole product announcements have been spoiled by leaks to the media. The main facts about the iPhone X and the Apple Watch 3 had been leaked to the media before the splashy launch event, leaving Apple executives to go through the motions of delivering big surprises from the stage. Apple says leaked information can depress sales of existing product models, and give competitors more time to respond to features coming in future models. “We want the chance to tell our customers why the product is great, and not have that done poorly by someone else,” the memo says.

Bloomberg’s Gurman is himself one of the main media beneficiaries of leaks from Apple employees. But that’s not where all the leaks come from. Many come from people at Apple’s suppliers who know the company’s plans–and some of them get paid to tell what they know. Apple says it’s Global Security team has worked “hand-in-hand” with its suppliers to eliminate leaks, but was not specific about its success.